Datasheet

REV. 0
ADuC816
–25–
SFR INTERFACE TO THE PRIMARY AND AUXILIARY
ADCS
Both ADCs are controlled and configured via a number of SFRs
that are mentioned here and described in more detail in the
following pages.
ADCSTAT: ADC Status Register. Holds general status of
the Primary and Auxiliary ADCs.
ADCMODE: ADC Mode Register. Controls general modes
of operation for Primary and Auxiliary ADCs.
ADC0CON: Primary ADC Control Register. Controls
specific configuration of Primary ADC.
ADC1CON: Auxiliary ADC Control Register. Controls
specific configuration of Auxiliary ADC.
SF: Sinc Filter Register. Configures the decimation
factor for the Sinc3 filter and thus the Primary
and Auxiliary ADC update rates.
ICON: Current Source Control Register. Allows
user control of the various on-chip current
source options.
ADC0H/M*: Primary ADC 16-bit conversion result held in
these two 8-bit registers.
ADC1H/L: Auxiliary ADC 16-bit conversion result held
in these two 8-bit registers.
OF0H/M*: Primary ADC 16-bit Offset Calibration Coeffi-
cient held in these two 8-bit registers.
OF1H/L: Auxiliary ADC 16-bit Offset Calibration Coeffi-
cient held in these two 8-bit registers.
GN0H/M*: Primary ADC 16-bit Gain Calibration Coeffi-
cient held in these two 8-bit registers.
GN1H/L: Auxiliary ADC 16-bit Gain Calibration Coeffi-
cient held in these two 8-bit registers.
*To maintain code compatibility with the ADuC824, it is the low-byte SFR
associated with these register groups that is omitted on the ADuC816.
ADCSTAT (ADC Status Register)
This SFR reflects the status of both ADCs including data ready, calibration and various (ADC-related) error and warning condi-
tions including reference detect and conversion overflow/underflow flags.
SFR Address D8H
Power-On Default Value 00H
Bit Addressable Yes
0YDR1YDRLACFERXON0RRE1RRE------
Table III. ADCSTAT SFR Bit Designations
Bit Name Description
7 RDY0 Ready Bit for Primary ADC.
Set by hardware on completion of ADC conversion or calibration cycle.
Cleared directly by the user or indirectly by write to the mode bits to start another Primary
ADC conversion or calibration. The Primary ADC is inhibited from writing further results to its
data or calibration registers until the RDY0 bit is cleared.
6 RDY1 Ready Bit for Auxiliary ADC.
Same definition as RDY0 referred to the Auxiliary ADC.
5 CAL Calibration Status Bit.
Set by hardware on completion of calibration.
Cleared indirectly by a write to the mode bits to start another ADC conversion or calibration.
4 NOXREF No External Reference Bit (only active if Primary or Auxiliary ADC is active).
Set to indicate that one or both of the REFIN pins is floating or the applied voltage is below a
specified threshold. When Set conversion results are clamped to all ones,if using ext. reference.
Cleared to indicate valid V
REF
.
3 ERR0 Primary ADC Error Bit.
Set by hardware to indicate that the result written to the Primary ADC data registers has
been clamped to all zeros or all ones. After a calibration this bit also flags error conditions that
caused the calibration registers not to be written.
Cleared by a write to the mode bits to initiate a conversion or calibration.
2 ERR1 Auxiliary ADC Error Bit.
Same definition as ERR0 referred to the Auxiliary ADC.
1 --- Reserved for Future Use.
0 --- Reserved for Future Use.
REV. A